1. Technical Field.
The present invention relates generally to the field of catheters for use in applications that require blood, fluids, medicated solutions, and other solutions to be removed from and introduced into a person. More particularly, the present invention relates to catheters having dual or multiple independent catheters in which a practitioner can control the distance of separation between the lumens at the distal end of the catheter.
2. Prior Art.
Hemodialysis, one procedure that requires the introduction and removal of blood from a patient, is a routine treatment for patients with renal failure. When patients are placed on hemodialysis, such patients require the placement of a catheter into a large blood vessel through a subcutaneous tunnel. In conventional procedures including the Seldinger technique, the catheter is inserted into the patient's blood vessel. This catheter, termed a hemodialysis catheter, is connected to a hemodialysis machine and is the vital connection between the patient and the hemodialysis unit. Once the practitioner has properly inserted the hemodialysis catheter into the patient, reliable hemodialysis can be performed for weeks to months using the placed catheter.
U.S. Pat. Nos. 6,190,349 and 5,947,953 to Ash et al. disclose a multiple catheter assembly and methods for inserting the same, in which first and second catheters are connected by a splittable membrane. The catheter assemblies in Ash '349 and Ash '953 comprise at least two independent catheters that are splittable to a length not predetermined by the catheter assembly. As the catheter assemblies in Ash '349 and Ash '953 are splittable as such, it may be possible to split or separate the catheters from each other within the assembly substantially beyond a desired or desirable length, which in some cases can impair the function of the catheter assembly. The thinness of the membrane initially holding the two lumens to each other makes this a likely possibility. Similarly, once the Ash '349 and Ash '953 lumens are split from each other, they cannot be reattached to each other.
U.S. Pat. No. 6,001,079 to Pourchez discloses a multilumen catheter comprising two lumens defined by a single wall for guiding a fluid. The Pourchez '079 catheter is for the circulation of at least one fluid between a patient's body cavity or vessel and a fluid circulating means. Although the Pourchez '079 catheter has separated catheter lumen tips, the distance between the lumen tips is predetermined and is not adjustable. Further, the unseparated portion of the lumens of the Pourchez '079 catheter are joined together and are not independent as they share a common wall. As the Pourchez '079 catheter has a set separation distance between the two lumens, which cannot be changed, the Pourchez '079 catheter may not be useful for a wide variety of sizes of patients.
Accordingly, there is a need for an improved catheter, more particularly a hemodialysis catheter with improved stability and performance. Further, there is a need for a catheter that can remain within a patients with less chest discomfort. It is to this and other needs that the present invention is directed.